There is an increasing need for detection of very low level concentrations of narcotic and explosive vapors. Security personnel in airports and other sensitive areas are currently using apparatus that sense these vapors in the parts per trillion (ppt) range. At the present writing, the National Institute for Standards and Technology does not have standards for explosive vapors; therefore, a portable calibrated vapor generator source is critically needed in the field to test and calibrate those vapor detection devices such as that disclosed in U.S. Pat. No. 5,157,261 issued Oct. 20, 1992, which uses fiber optic spectroscopy and changes in fluorescence to detect explosives. U.S. Pat. No. 4,820,920 issued Apr. 11, 1989, discloses a second method and apparatus for detecting explosive or illegal drugs by microwave or RF radiation and then injecting the substance into a mass spectrometer for spectrum analysis.
It is desirable to be able to test and calibrate these type devices in the field to determine operability and accuracy at low concentrations. It is therefore the purpose of this invention to describe an apparatus and method for calibrating these detection devices in the field using a portable calibrated vapor generator source.